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Full-Text Articles in Engineering
Explosively Formed Projectile Soft-Recovery Force Analysis, Laurin Bookout, Phillip R. Mulligan, Jason Baird
Explosively Formed Projectile Soft-Recovery Force Analysis, Laurin Bookout, Phillip R. Mulligan, Jason Baird
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
The design of a soft-recovery system is critical to a researcher's ability to analyze hypervelocity projectiles. The researcher may decide to use one method over another based on several criteria, including whether or not non-deformed projectile measurements are required. This report analyzes the forces two different soft-recovery methods impart on the projectiles collected. Method 1 utilized three polyethylene water barrels placed “end-to-end” horizontally, providing 2.6 meters (9 feet) of water to stop the projectile. Method 2 is a modification of the soft-recovery method utilized in “Soft-Recovery of Explosively Formed Penetrators” by Lambert and Pope. This method utilizes a series of …
Stochastic Simulation Of Entangled Polymeric Liquids In Fast Flows: Microstructure Modification, Joontaek Park, David W. Mead, Morton M. Denn
Stochastic Simulation Of Entangled Polymeric Liquids In Fast Flows: Microstructure Modification, Joontaek Park, David W. Mead, Morton M. Denn
Chemical and Biochemical Engineering Faculty Research & Creative Works
We have modified the full-chain stochastic tube (XDS) model developed by Xu et al. [J. Rheol. 50, 477-494 (2006)] to simulate the rheology of entangled melts and solutions of linear monodisperse polymers. The XDS model, which has a single adjustable parameter that is equivalent to the Rouse time, successfully describes steady and transient shear and normal stress data at low to moderate rates, but the results deviate systematically from experimental data at high rates. The algorithm for re-entanglement was revised, and a configuration- dependent friction coefficient (CDFC), as originally proposed by Giesekus, was incorporated to account for microstructural change of …
Effect Of Coal Fines On The Shear Strength And Deformation Characteristics Of Ballast, S S. Nimbalkar, Buddhima Indraratna, Cholachat Rujikiatkamjorn, M Martin
Effect Of Coal Fines On The Shear Strength And Deformation Characteristics Of Ballast, S S. Nimbalkar, Buddhima Indraratna, Cholachat Rujikiatkamjorn, M Martin
Faculty of Engineering - Papers (Archive)
Ballast is the most common material supporting the rail track structure due to its large shear strength, high load bearing capacity and free-drainage. However, the fouling of ballast effects deterioration of track performance, and eventually demands track cleaning. Fouling refers to the progressive intrusion of fines into the ballast layer and subsequently filling the voids. Coal spilling from wagons during transport, sleeper and ballast degradation and soil pumping from soft subgrade are the major factors contributing to ballast fouling. Queensland rail network suffers mainly due to ballast breakdown and intrusion of coal fines. The maintenance costs of ballasted tracks can …
Effects Of Initial Static Shear On Liquefaction And Large Deformation Properties Of Loose Saturated Toyoura Sand In Undrained Cyclic Torsional Shear Tests, Gabriele Chiaro, Junichi Koseki, Takeshi Sato
Effects Of Initial Static Shear On Liquefaction And Large Deformation Properties Of Loose Saturated Toyoura Sand In Undrained Cyclic Torsional Shear Tests, Gabriele Chiaro, Junichi Koseki, Takeshi Sato
Faculty of Engineering - Papers (Archive)
This study focused on the role which static shear plays on the large deformation behavior of loose saturated sand during undrained cyclic loading. A series of undrained cyclic torsional shear tests was performed on saturated Toyoura sand specimens up to single amplitude shear strain exceeding 50%. Three types of cyclic loading patterns, i.e., stress reversal, intermediate and non-reversal, were employed by varying the initial static shear level and the cyclic shear stress amplitude. The observed types of failure could be distinguished into liquefaction (cyclic and rapid flow) and residual deformation by comparing both monotonic and cyclic undrained behavior. It was …
Deformation And Degradation Of Clay Fouled Ballast Subjected To Monotonic Loading, Nayoma Tennakoon, Buddhima Indraratna, Sanjay Nimbalkar, Cholachat Rujikiatkamjorn
Deformation And Degradation Of Clay Fouled Ballast Subjected To Monotonic Loading, Nayoma Tennakoon, Buddhima Indraratna, Sanjay Nimbalkar, Cholachat Rujikiatkamjorn
Faculty of Engineering - Papers (Archive)
Railways offer an efficient and economic transport mode in many countries including Australia, China and USA. Conventionally, rail tracks are positioned on ballast due to several potential benefits, including economy (availability and abundance), rapid drainage and high load bearing capacity. However, the ballast becomes contaminated due to intrusion of pumped subgrade material (e.g. clay and silt). This is one of the primary reasons for rapid track deterioration. In severe circumstances, fouled ballast needs to be cleaned or replaced to maintain the desired track resiliency, load bearing capacity and the track alignment, all of which influence the level of safety. In …
Hot Deformation Of Cast And Extruded Tial: An In-Situ Diffraction Study, Thomas Schmoelzer, Klaus-Dieter Liss, Svea Mayer, Kun Yan, Mark H. Reid, Rian J. Dippenaar, Matthew Peel, Helmut Clemens
Hot Deformation Of Cast And Extruded Tial: An In-Situ Diffraction Study, Thomas Schmoelzer, Klaus-Dieter Liss, Svea Mayer, Kun Yan, Mark H. Reid, Rian J. Dippenaar, Matthew Peel, Helmut Clemens
Faculty of Engineering - Papers (Archive)
Intermetallic TiAl alloys are a class of innovative high-temperature materials which are developed to replace the substantially denser Ni-base alloys in low-pressure turbine blades of jet engines. By streamlining the production process of these parts, a substantial decrease in production costs can be achieved. To this end, a profound knowledge of the microstructural processes occurring during hot deformation is a prerequisite. To investigate the microstructural development during forming operations, cast and extruded as well as only cast specimens were hot-deformed and the microstructural development investigated in-situ by means of a novel diffraction method. This powder diffraction method utilizes the behavior …
Non-Uniform Stress Distribution In Frp-Wrapped Circular Concrete Columns Under Uniform Axial Deformation, S Q. Li, J F. Chen, Tao Yu, J G. Teng
Non-Uniform Stress Distribution In Frp-Wrapped Circular Concrete Columns Under Uniform Axial Deformation, S Q. Li, J F. Chen, Tao Yu, J G. Teng
Faculty of Engineering and Information Sciences - Papers: Part A
The confinement of concrete columns using bonded FRP wraps has become a popular retrofit technique. Through extensive research in the last two decades, many stress-strain models have been developed for concrete in FRP-wrapped circular columns. All these models assume that the stress state is axisymmetric in an FRP-wrapped circular concrete column under concentric axial compression. This implies that the FRP wrap is assumed to be axisymmetric in geometry, but in reality such axisymmetry is not realised due to the existence of an overlapping zone. This paper presents a finite element investigation into the stress state in FRP-wrapped circular concrete columns …